Iran's Supreme Leader Ayatollah Ali Khamenei on Tuesday accused the United States of trying to divide Iraq along sectarian and ethnic lines and urged Iraqis to withstand any such plans.
Shi'ite Muslim power Iran wields great influence in Iraq, which has a majority Shi'ite population.
Its military advisers are helping direct Baghdad's campaign against Sunni Islamist militant group Islamic State, which seized around a third of Iraq's territory last year.
It was not clear if Khamenei was referring to a specific incident, but Iran has protested about U.S. policy in Iraq several times this year.
"The Americans must not be allowed to consider Iraq as their personal property ... and dare to openly talk about disintegration of Iraq," Khamenei said according to his website.